Light-operated control device

ABSTRACT

A light-operated control device including a spherical housing mounted on a second housing for universal swiveling movement relative thereto. An arm extending out from the second housing overlies the sphere and is clamped thereagainst to secure the sphere in any selected position. A photocell mounted in the sphere has a light-sensitive side which faces out through an aperture in a side of the sphere. A light-channeling passage having deflector surfaces along its sides extends between the aperture and the light-sensitive side of the photocell. This passage inhibits ambient light from striking the photocell. The photocell is connected to control circuitry in the second housing by elongated flexible conductors which permit free swiveling of the sphere.

United States Patent Myers [4 July 25, 1972 [54] LIGHT-OPERATED CONTROLDEVICE 3,469,103 9/1969 Erpel ..250 219 D 3,535,539 10/1970 Malespina eta1... ..250/239 [72] Invent Myers Gwve 3,619,629 11/1971 Matthews..2s0/234 [73] Assignee: Xercon, Inc., Portland, Oreg.

FOREIGN PATENTS OR APPLICATIONS [22] F1led: March 25, 1970 16,992 1888Great Britain ..350/175 [21] Appl. No.: 22,611

Primary Examiner-Walter Stolwein 52 us. c1 .250/239, 250/227, 250/221, &Ham/e" 250/234 51 1111.01 ..H0lj 3/14 ABSTRACT [58] Field ofSearch..250/239, 228,219 D,2l9 DC. A H h g t-operated control device 1nclud1nga spherical housmg 250/227 23 219 350/968 mounted on a second housingfor universal swiveling move- 356/172 138 ment relative thereto. An armextending out from the second housing overlies the sphere and is clampedthereagainst to [56] References C'ted secure the s here in any selectedposition. A photocell p UNITED STATES PATENTS mounted in the sphere hasa light-sensitive side which faces out through an aperture in a s1de 0fthe sphere. A hght-chan- 1,550,197 8/1925 Berry ..350/96 nelin passagehaving deflector surfaces along its sides extends 2,390,351 6/1959between the aperture and the light-sensitive side of the 3 7/1963photocell. This passage inhibits ambient light from striking the3,145,249 8/1964 photocell. The photocell is connected to controlcircuitry in 3,360,656 12/1967 250/239 the second housing by elongatedflexible conductors which 2,713,642 7/1955 Powers et al... 250/239 Xpermit f swiveling fth sphere 2,778,952 1/1957 Balde ....250/239 X2,957,085 10/1960 Faulhaber ..250/239 X 1 Claim, 4 Drawing FiguresLIGHT-OPERATED CONTROL DEVICE This invention relates to a light-operatedcontrol device.

A general object of the invention is to provide a novel lightoperatedcontrol device with includes a light-responsive element mounted in sucha manner that it may be directed easily in any desired direction.

More specifically an object is to provide such a device wherein thelight-responsive element is in a housing which is mounted for universalswiveling movement. The device also includes means for securing thehousing in any selected position. The device thus permits alight-sensitive side of the element to be directed as desired and thensecured in such position.

Another object is to provide such a novel light-operated control devicewherein the housing in which the light-responsive element is mounted isseated on a second housing for universal swiveling movement relativethereto. The second housing holds control circuitry to which thelight-responsive element may be electrically connected. With thisconstruction the housing for the light-responsive element may be madesmaller than would be possible if all control circuitry were to bemounted therein. Also, the housing mounting the control circuitry is theone used to anchor the device in an installation.

Yet another object is to provide for such a device, lightchannelingmeans mounted adjacent the light-sensitive side of the light-responsiveelement. The light-channeling means provides an elongated passage withdeflector surfaces along its sides. the deflector surfaces beingdisposed at substantial angles to the axis of the passage. Thisconstruction assures that the light-sensitive side of the element iseffected primarily by light beamed directly thereagainst. Thelight-channeling means minimizes the effect of ambient light.

These and other objects and advantages will become more fully apparentas the following description is read in conjunction with the drawings,wherein:

FIG. 1 is perspective view ofa light-operated control device constructedaccording to the invention;

FIG. 2 is an enlarged cross-sectional view taken along the line 2-2 inFIG. 1;

FIG. 3 is an exploded view of a pair of mating parts which comprise aportion ofthe invention; and

FIG. 4 is a simplified schematic diagram ofa switching circuit in thedevice.

Referring now to the drawings, and first more specifically to FIG. 1, atis indicated generally a light-operated control device according to theinvention. The device includes a spherical housing 14 mounted on a boxhousing 16.

Referring first to housing I4, it includes a pair of hollow hemisphericportions 14a, 14b which are joined along their edges to form a hollowsphere. An aperture is provided on one side of housing 14. As is bestseen in FIG. 2, a pair of bores 22, 24 extend through housing 14, bore22 being displaced 90 from aperture 20, and bore 24 being displaced 90from bore 22 or diametrically opposite aperture 20.

Housing 16 has an opening 26 extending through its top. A rubber O-ringseal 28 rests on a lip 29 surrounding opening 26. The lip and sealprovide a seat on which housing 14 rests.

A mounting bracket, indicated generally at 30, is mounted on housing 16for securing housing 14. Bracket 30 includes a base portion 32 and apair of curved expanses 34, collectively comprising an arm, whichproject upwardly from base 32 and curve over the top of housing I4.Expanses 34 converge on progressing upwardly hand have a ring 36 joinedto their ends which seats on the top of housing 14. A pair of screws,such as that indicatedat 38 in FIG. 2, extend through bores in base 32and into accommodating threaded bores 40 in housing 16.

With screws 38 loosened, housing 14 is free to swivel about multipleaxes to any desired position. With screws 38 tightened the ring on themounting bracket is drawn tightly against housing 14 to secure thehousing in any selected position.

In FIG. I, it will be noted that a second pair of threaded bores 42 areprovided in the top of housing 16, whereby bracket 30 may be mountedadjacent the opposite side of the generally housing. Since mountingbracket 30 and the seat provided on the top of housing 16 permituniversal swiveling of housing l4 about multiple axes, they are referredto collectively herein as a universal mounting.

Referring now to FIG. 2, a light-responsive element, or photocell, 50having a light-sensitive side 50a is mounted within housing 14.Photocell 50 is supported by mounting structure indicated generally at54 in housing 14 with its side 50a directed toward aperture 20.

A photocell which has been found to work well in such a device is acadmium selenide type, manufactured by National Semiconductors Ltd., andidentified by manufacuteres number NSL-353l and NSL-356l. Thesephotocells each have a peak sensitivity in the red part of the spectrum(approximately 7,100 Angstroms) and thus are effected primarily by lightsources in this range. If the photocell is directed at a light sourceproducing light in this part of the spectrum its response will beaffected primarily by such light source. and ambient light fromartificial sources, such as flourescent or mercury vapor lamps which aregenerally nearer the ultraviolet part of the spectrum, will have minimaleffect on the photocell.

Structure 54, as is best seen in FIG. 3, is composed of a pair of matingsemicylindrical components 54a, 5412 which, when mounted in housing 14,join along their flat facing surfaces. Components 54a, 54b aresubstantially mirror images of each other, with the exception thatcomponent 54b has multiple pins 54 extending outwardly therefrom andcomponent 54a has accommodating bores for receiving these pins toproperly align the components when fit together.

With components 54a, 54b fit tightly together to form mounting structure54, and referring specifically to FIG. 2, they provide a socket 60within which the photocell is firmly seated. A pair of ears 62 extendlaterally outwardly from opposite sides of socket 60. These ears havenotches therein which engage pins 64 which are secured to onehemispheric portion of housing 14 and project inwardly therefrom. Mounting structure 54 is firmly seated in housing 14 by being wedged betweenpins 64 and the left wall of housing 14 as seen in FIG, 2.

Wall structure 66 of mounting 54 defines a tunnel, or passage, 68 openat both ends, which extends forwardly, to the left in FIG. 2, from thelight-sensitive side of photocell 50 to aperture 20. Annular grooves, 70are defined in wall structure 66 opening inwardly toward passage 68. Thesides of grooves 70. also referred to herein as deflector surfaces, aredisposed at substantial angles to the central axis of the passage.

The passage and annular grooves defined by wall structure 66 may befilled with a translucent material which permits light to passtherethrough to the photocell. A material which has been found to workwell is an elastomeric silicone rubber such as the material manufacturedby General Electric under this generic name, and having a manufacturersnumber RTV-IOS. This material provides a bond to hold components 54a,54b together and to secure the photocell solidly in the unit. Thematerial maintains its bond and elasticity throughout a wide temperaturerange, thus providing good shock protec tion for the photocell in anyapplication. The material also seals out dust.

The passage and annular grooves provided by wall structure 66 act aslight-channeling means which provides a course along which lightdirected straight through aperture 20 may pass substantiallyunobstructed to the light-sensitive side of the photocell. Lightentering the aperture at an angle will strike one of the angularlydisposed sides of the annular grooves and be reflected away fromthe'light-sensitive side of the photocell. Thus, light entering housing14 directly through aperture 20 will have maximum effect on side 5011while light entering the aperture at an angle will have minimum effectthereon.

A lens 74 mounted in the aperture serves to focus light more directly asits enters the housing. The lens may be made of glass, or other easilycleaned hard translucent substance, to protect the underlyingelastomeric material filling the passage.

A pair of conductors 78, 80 are connected to element 50 and are shown inFIG, 2 extending out of housing 14 through bore 22 and into housing 16.This positioning of the conductors permits swiveling of housing 14 todirect side 50:: of the photocell to any side and at a substantial angleto the horizontal.

Should it be desired to direct side 50:! straight up, or at some smallangle from the vertical, conductors 78,. 80 may be extended out ofhousing 14 through bore 24, which bore, with the housing turned to facephotocell 50 upwardly, would be in communication with opening 26 inhousing 16. With the photocell directed straight up it sees through theopening in ring 36. As has been mentioned previously mounting bracket 30may be secured to housing 16 adjacent the opposite side of the housingif it is desired to direct the photocell in a direction opposite thedirection it points in the illustrations. Further, the space betweenexpanses 34 of the bracket will be adequate in most cases for providingvisual clearance for the photocell without repositioning the bracket.

Referring now to FIG. 4, a schematic ofa switching circuit in theinvention is illustrated generally at 90. The switching circuit, ofwhich photocell 50 is a part, is connected between an AC power source 92and a load 94. Control circuitry, which comprises a part of theswitching circuit, is mounted within housing 16 on a terminal blockindicated generally at Q6 in FIG. 1 and illustrated by a dot-dashoutline in FIG. 4.

The control circuit within housing 16 includes a switching element 98,comprising a bi-directional triode semiconductor, commonly known as aTriac, which is connected in series with the power source and load. TheTriac is provided with first and second anodes 102, 104, respectively,and a gate electrode 106. Anode 102 is connected to the power source andanode 104 is connected to load 94. Gate electrode 106 is connected tothe cathode of an avalanche diode 108. The anode of diode 108 isconnected to the common juncture of a biasing capacitor 114 andconductor 80 connected to photocell 50. A filter capacitor 112 isconnected in parallel with the Triac.

Wall structure 66 of mounting structure 54 is illustrated schematicallyin FIGv 4 adjacent photocell 50. A lamp, or light source, 120 ispositioned opposite photocell 50, whereby its light is directed towardphotocell 50 along a course through the passage provided by wallstructure 66. As mentioned previously the light source preferably is onewhich emits light in the red part of the spectrum.

Describing now the operation of the light-operated control device of theinvention. With screws 38 loosened, housing 14 may be swiveled asdesired to direct side 50a of photocell 50 toward a light source to bemonitored. With the aperture and photocell directed as desired, screws38 are tightened to draw the mounting bracket tightly against housing 14frictionally to hold it in its adjusted position. As has been notedpreviously, the light source toward which photocell 50 is directed willhave maximum cfiect thereon, since the light from such source will havean unobstructed passage to the photocell. Light directed toward thephotocell from other sources will be deflected by the sides of annulargrooves 70 to minimize its effect on element 50.

The supply of electrical current from source 92 to load 94 is controlledby the switching circuit and is dependent on whether light from sourcereaches photocell 50 or is blocked from the photocell. Such controlfunction is described in detail in the previously mentioned copendingapplication.

If it becomes necessary to monitor the operation of a light source atanother location, it is a simple matter to readjust the position ofhousing 14 to direct the light-sensitive side of photocell 50 toward thenew light source to be monitored.

While an embodiment of the invention has been described I herein, itshould be obvious to those skilled in the art that variations andmodifications are possible without departing from the spirit of theinvention.

It is claimed and desired to secure by Letters Patent:

1. A light-operated control device comprising asubstantially sphericalfirst housing, an aperture extending through a side of said housingthrough which light may enter the housing,

a light-responsive element mounted on said housing positioned to receivelight entering the housing through said aperture,

a second housing,

control circuitry mounted in said second housing.

mounting means mounting said first housing outwardly of a side of saidsecond housing for universal swiveling movement relative to said secondhousing between multiple adjusted positions with the light-responsiveelement facing in different directions in said adjusted positions, saidmounting means including means defining a seat on said side of saidsecond housing receiving a side portion of said first housing, and anarm mounted on and projecting outwardly from the second housing havingan engaging portion forming a seat which receives another side portionof the first housing which other side portion is diametrically oppositethe first-mentioned side portion of the first housing, saidlightresponsive element facing to one side of said first-mentioned andother side portions of the first housing,

adjustable means for releasably clamping said seats against said firsthousing frictionally to secure the first housing relative to said secondhousing in a selected adjusted position, and

means electrically interconnecting said light-responsive element andsaid control circuitry and accommodating such universal swivelingmovement of the first housing relative to the second housing.

1. A light-operated control device comprising a substantially sphericalfirst housing, an aperture extending through a side of said housingthrough which light may enter the housing, a light-responsive elementmounted on said housing positioned to receive light entering the housingthrough said aperture, a second housing, control circuitry mounted insaid second housing, mounting means mounting said first housingoutwardly of a side of said second housing for universal swivelingmovement relative to said second housing between multiple adjustedpositions with the light-responsive element facing in differentdirections in said adjusted positions, said mounting means includingmeans defining a seat on said side of said second housing receiving aside portion of said first housing, and an arm mounted on and projectingoutwardly from the second housing having an engaging portion forming aseat which receives another side portion of the first housing whichother side portion is diametrically opposite the first-mentioned sideportion of the first housing, said light-responsive element facing toone side of said first-mentioned and other side portions of the firsthousing, adjustable means for releasably clamping said seats againstsaid first housing frictionally to secure the first housing relative tosaid second housing in a selected adjusted position, and meanselectrically interconnecting said light-responsive element and saidcontrol circuitry and accommodating such universal swiveling movement ofthe first housing relative to the second housing.